Salt forms of organic compound

ABSTRACT

The present invention relates to novel salt forms of 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine, a DPP-4 inhibitor and their use in pharmaceutical compositions useful in the treatment of type 2, diabetes, as well as their production.

The present invention relates to certain salt forms of a xanthine derivative, namely certain salt forms of the pharmaceutically active compound 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine, including amorphous and crystalline forms thereof (including solvate and hydrate forms), and to processes for the manufacture thereof, as well as to the use thereof in pharmaceutical compositions. Methods for treating and/or preventing of diseases which are associated with the enzyme dipeptidyl peptidase IV (DPP-4), such as e.g. metabolic diseases, particularly diabetes (especially type 2 diabetes mellitus) and diseases related thereto, with these compounds as defined herein optionally in combination with one or more other active substances are also contemplated.

In general, salts, solvates, hydrates, polymorphs, crystalline and amorphous forms of a given substance differ often in crystal habits and/or crystalline solid state properties and hence they may have different physical and pharmaceutical properties such as, for example, shape, density, hardness, deformability, stability, purity, hygroscopicity, flowability, compactation, solubility and/or dissolution properties or the like, which may influence, for example, their manufacturability, processability, pharmacokinetic profile (e.g. bioavailability), drug stability (shelf life), administrability and/or formulability or the like, such as e.g. their suitability as solid, semi-solid or liquid pharmaceutical dosage forms, e.g. as tablets, capsules, suspensions, solutions, suppositories or other pharmaceutical dosage forms (including e.g. sustained release formulations or combination preparations comprising a further active ingredient).

A number of xanthine derivatives are already known in the prior art as DPP-4 inhibitors.

The enzyme DPP-4 (dipeptidyl peptidase IV) also known as CD26 is a serine protease known to lead to the cleavage of a dipeptide from the N-terminal end of a number of proteins having at their N-terminal end a prolin or alanin residue. Due to this property DPP-4 inhibitors interfere with the plasma level of bioactive peptides including the peptide GLP-1 and are considered to be promising drugs for the treatment of diabetes mellitus.

For example, DPP-4 inhibitors and their uses, particularly their uses in metabolic (especially diabetic) diseases, are disclosed in WO 2002/068420, WO 2004/018467, WO 2004/018468, WO 2004/018469, WO 2004/041820, WO 2004/046148, WO 2005/051950, WO 2005/082906, WO 2005/063750, WO 2005/085246, WO 2006/027204, WO 2006/029769 or WO2007/014886; or in WO 2004/050658, WO 2004/111051, WO 2005/058901 or WO 2005/097798; or in WO 2006/068163, WO 2007/071738 or WO 2008/017670; or in WO 2007/128721 or WO 2007/128761.

The compound 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine is an orally active DPP-4 inhibitor with therapeutic value for treating type 2 diabetes mellitus, obesity and related diseases.

It has now been found that certain salts of 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine have surprising and useful properties.

Thus, the present invention relates to compounds which are acid addition salts of 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine, especially pharmaceutically acceptable inorganic or organic acid addition salts. Particular mention may be made of the physiologically acceptable salts with inorganic or organic acids customarily used in pharmacy, such as e.g. any of those inorganic and organic acids mentioned below. The salts include water-insoluble and, particularly, water-soluble salts.

Inorganic acids customarily used for forming pharmaceutically acceptable acid addition salts include, by way of example and not limitation, hydrochloric acid, hydrobromic acid, phosphoric acid, nitric acid, sulfuric acid, and the like.

Organic acids customarily used for forming pharmaceutically acceptable acid addition salts include, by way of example and not limitation, acetic acid, 2,2-dichloroacetic acid, adipic acid, ascorbic acid (D- or L-form thereof, especially the L-form thereof), aspartic acid (D- or L-form thereof, especially the L-form thereof), benzenesulfonic acid, benzoic acid, 4-acetamido-benzoic acid, camphoric acid ((+)- or (−)-form thereof, especially the (+)-form thereof), camphor-10-sulfonic acid ((+)- or (−)-form thereof, especially the (+)-form thereof), capric acid (decanoic acid), caproic acid (hexanoic acid), caprylic acid (octanoic acid), carbonic acid, cinnamic acid, citric acid, cyclamic acid, dodecylsulfuric acid, ethane-1,2-disulfonic acid, ethanesulfonic acid, 2-hydroxy-ethanesulfonic acid, formic acid, fumaric acid, galactaric acid, gentisic acid, glucoheptonic acid (D- or L-form thereof, especially the D-form thereof), gluconic acid (D- or L-form thereof, especially the D-form thereof); glucuronic acid (D- or L-form thereof, especially the D-form thereof), glutamic acid, glutaric acid, 2-oxo-glutaric acid, glycerophosphoric acid, glycolic acid, hippuric acid, isobutyric acid, lactic acid (D- or L-form thereof), lactobionic acid, lauric acid, maleic acid, malic acid (D- or L-form thereof), malonic acid, mandelic acid (D- or L-form thereof), methanesulfonic acid, naphthalene-1,5-disulfonic acid, naphthalene-2-sulfonic acid, 1-hydroxy-2-naphthoic acid, nicotinic acid, oleic acid, orotic acid, oxalic acid, palmitic acid, pamoic acid (embonic acid), propionic acid, pyroglutamic acid (D- or L-form thereof, especially the L-form thereof), salicyclic acid, 4-aminosalicyclic acid, sebacic acid, stearic acid, succinic acid, tartaric acid (D- or L-form thereof), thiocyanic acid, toluenesulfonic acid (especially the p-isomer thereof), undecylenic acid, and the like.

A class of above-mentioned organic acids includes carboxylic acid derivatives. Another class of above-mentioned organic acids includes sulfonic acid derivatives.

The acids may be monobasic or polybasic acids, illustrative polybasic acids are dibasic or tribasic. These polybasic acids can be, depending on their nature, substantially singly, twicely or tricely deprotonated, typically they are substantially singly deprotonated.

For example, in carboxylic acid salts the acid can be a mono- or polycarboxylic acid having one or, respectively, two or more carboxylic acid groups. In a first sub-class of polycarboxylic acid salts, the polycarboxylic acids in these salts can be substantially singly deprotonated, as for example in the case of a dicarboxylic acid salt having a 1:1 stoichiometry of free compound and dicarboxylic acid. In a second sub-class of polycarboxylic acid salts, the polybasic carboxylic acid and the free compound can be in a substantially 1:1 stoichiometry, irrespective of the number of carboxylic acid groups in the acid.

A sub-group of above-mentioned inorganic or organic acids includes, by way of example and not limitation, acetic, adipic, L-ascorbic, capric, carbonic, citric, fumaric, galactaric, D-glucoheptanoic, D-gluconic, D-glucuronic, glutamic, glutaric, glycerophosphoric, hippuric, hydrochloric, D- or L-lactic, lauric, maleic, (−)-L-malic, phosphoric, sebacic, succinic, sulphuric, (+)-L-tartaric and thiocyanic acid.

Another sub-group of above-mentioned inorganic or organic acids includes, by way of example and not limitation, alginic, benzenesulfonic, benzoic, (+)-camphoric, caprylic, cyclamic, dodecylsulfuric, ethane-1,2-disulfonic, ethanesulfonic, 2-hydroxy-ethanesulfonic, gentisic, 2-oxoglutaric, isobutyric, lactobionic, malonic, methanesulfonic, naphthalene-1,5-disulfonic, naphthalene-2-sulfonic, 1-hydroxy-2-naphthoic, nicotinic, oleic, orotic, oxalic, pamoic, propionic, (−)-L-pyroglutamic and p-toluenesulfonic acid.

The acids are employed in salt preparation—depending on whether a mono- or polybasic acid is concerned and depending on which salt is desired—in an equimolar quantitative ratio or one differing therefrom.

Thus, within the acid addition salts of this invention the acid and the free compound may be substantially in 1:1 stoichiometry or one differing therefrom, such as e.g. from about 1:2 to about 2:1 stoichiometry. Non-integral stoichiometry ratios may be also possible, such as e.g. 1:1.5 or 1.5:1.

A certain sub-group of acid addition salts with inorganic or organic acids includes, by way of example and not limitation, the hydrochloride, mesylate, hydrobromide, acetate, fumarate, sulfate, succinate, citrate, phosphate, maleate, tartrate, lactate, benzoate and carbonate salt.

Another certain sub-group of acid addition salts with inorganic or organic acids includes, by way of example and not limitation, the hydrochloride, sulphate, tartrate, maleate, citrate, phosphate, acetate, lactate and fumarate salt.

The invention also includes mixtures of salts.

Furthermore, any salt given herein is intended to embrace all tautomers, hydrates, solvates, crystalline, amorphous and polymorphous forms thereof, as well as mixtures thereof.

Those skilled in the art will appreciate that organic compounds can be isolated in association with solvent molecules or can form complexes with solvents in which they are reacted or from which they are precipitated, crystallized or isolated. According to expert's awareness, some of the salts according to this invention may contain, e.g. when isolated in solid form, varying or fixed amounts of solvents (including aqueous and/or non-aqueous solvents). Included within the scope of the invention are therefore solvates (including hydrates, organic solvates and mixed hydrates/organic solvates) of the salts according to this invention. Solvates of the salt forms according to this invention include stoichiometric and non-stoichiometric solvates. Preferably the solvent(s) used is a pharmaceutically acceptable solvent(s), e.g. water and/or ethanol or the like. The present invention embraces both the unsolvated and all solvated forms. Likewise, the present invention embraces all hydrate, anhydrous, hygroscopic and/or non-hygroscopic forms.

In a further aspect, the present invention relates to compounds which are solvates of the salts according to this invention either in simple, such as e.g. solvates comprising an organic solvent alone or water alone, or in mixed form, such as e.g. mixed solvates comprising at least one organic solvent, such as e.g. a low molecular weight aliphatic alcohol, with water (e.g. mixed hydrates/solvates), or mixed solvates comprising at least two different organic solvents with or without water, in any mixing ratios, including homosolvates (solvates in which there is solely one type of solvent) and heterosolvates (solvates in which there are two or more different types of solvents).

For more detailed example, solvates of the salts according to this invention include hydrates and alcoholates (solvates with alcohol, such as e.g. ethanol) as well as mixtures thereof (including mixed hydrates/alcoholates).

The one or more solvents may be present in an non-stoichiometric amount or in a stoichiometric amount, such as e.g. 0.5:1, 1:1, 1.5:1, 2:1, 3:1, or 4:1 molar ratio based on the amount of the solvate-free salt. Where the crystalline forms are solvated, they may contain, for example, up to four molecules of solvens, more usually up to two or three molecules, e.g. one molecule of solvent or two molecules of solvents. Non-stoichiometric solvates may also be formed in which the number of molecules of solvent present is less than one or is otherwise a non-integer, such as e.g., where there is less than one molecule of solvent present, there may be for example 0.4, or 0.5, or 0.6, or 0.7, or 0.8, or 0.9 molecules of solvent present per molecule of compound. For example, solvates or hydrates of the salts according to this invention include, without being limited to, hemi-, mono-, sesqui-, di-, tri- and tetra-solvates or -hydrates, respectively. Stoichiometric and non-stoichiometric mixed solvates of these hydrates with one or more organic solvents (such as e.g. with an alcohol, particularly ethanole) in any mixing ratios are also contemplated within this invention.

In a certain embodiment, the present invention relates to hydrates, solvates with ethanol (ethanolates) and mixed hydrates/ethanolates of the salts of this invention.

Within the solvates of this invention, the solvent molecules can be incorporated into the solid-state structure (such as e.g. they may be become trapped in the crystals upon isolation) or not (such as e.g. they may be retained on the surface of the crystals). When the solvent or water is tightly bound (as e.g. in isolated site solvates), the complex has often a well defined stoichiometry independent of humidity. When, however, the solvent or water is weakly bound (as e.g. in channel solvates and in hygroscopic compounds), the water/solvent content is often dependent on humidity and/or drying conditions and the non-stoichiometry is the norm.

Pharmaceutically non-acceptable salts (including their solvates and hydrates), which can be obtained, for example, as process products during the manufacture on an industrial scale, can be converted into pharmaceutically acceptable salts (including their solvates and hydrates) by processes known to the person skilled in the art, e.g. by salt and/or solvate exchange or displacement, or via the salt- and/or solvate-free compound (with or without isolation).

Salts (including solvates, hydrates and/or other forms) which are unsuitable for pharmaceutical uses but which can be employed, for example, for the isolation or purification of the free compound 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine or of their pharmaceutically acceptable salts (including solvates, hydrates and/or other forms), are also included within this invention.

A particular embodiment of this invention relates to an acid addition salt of 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine selected from the group consisting of a besylate salt, a hydrobromide salt, a benzoate salt, an esylate salt, a fumarate salt, a mesylate salt, a salicylate salt, a tosylate salt, a hydrochloride salt, a glycolate salt, a malonate salt and a gentisate salt, as well as the solvates, in particular the organic solvates, the hydrates and the mixed organic solvates/hydrates thereof.

The salts (including their solvate, hydrate and/or other forms) of this invention can be obtained by methods known to the skilled person for making acid addition salts, e.g. these salts can be prepared (e.g. in situ) during the final reaction, deprotection, isolation, purification and/or further processing of the free compound (or prodrug, precursor or protected compound), or by reacting the free compound with the desired acid or a suitable anion exchange reagent, such as e.g. via a process comprising one or more of the steps described herein. Typically, the free compound is combined with the desired acid, e.g. by dissolving, dispersing or slurrying the free compound in a suitable solvent or mixture of solvents, which contains the desired acid, or to which the desired acid (optionally dissolved in a suitable solvent or mixture of solvents) is then added, or vice versa, with or without heating (e.g. dissolving, mixing and/or reacting can be conducted at ambient temperature or at elevated temperature (such as e.g. from about 30° C. to 70° C. or from 40° C. to 60° C.) or at the boiling temperature of the solvent(s) used, such as temperatures up to 100° C. may be applied to form solutions). The salts can be isolated, e.g. by filtering, crystallization, precipitating e.g. with a nonsolvent for the addition salt or by cooling, or by concentrating (e.g. by heating, removing or evaporating the solvent), and, if desired, purified, e.g. by re-crystallization from an appropriate re-crystallization solvent or mixture of solvents by methods customary to one of skill in the art (e.g. analogously or similarly as described afore), and/or, if required, the process further comprises, at a suitable stage, removing or separating any undesired material or impurities, and finally, optionally, the salts may be washed and/or dried.

In general, solvents, which the skilled person may consider within this invention, may include, without being limited to, organic, non-aqueous or aqueous, protic or aprotic, polar or apolar solvents, such as, for example, ketones such as e.g. acetone, methyl ethyl ketone, methyl propyl ketone, methyl tert- or isobutyl ketone or the like, lactones such as e.g. valerolactone, ethers such as e.g. diethyl ether, diisopropyl ether, ethylene glycol dimethyl ether, tetrahydrofuran, dioxane or the like, hydrocarbons such as e.g. toluene, hexane or the like, chlorinated hydrocarbons such as e.g. methylene chloride, chloroform or the like, low-molecular-weight aliphatic alcohols such as e.g. methanol, ethanol, 1-propanol, isopropanol, butanol or the like, esters such as e.g. acetic acid lower alkyl esters (e.g. ethyl acetate) or the like, amides or lactames such as e.g. N,N-dimethylformamide, N-methyl-2-pyrrolidone or the like, nitriles such as e.g. acetonitrile or the like, or sulfoxides such as e.g. DMSO or the like, or water, or mixtures thereof.

Appropriate solvents or nonsolvents may be determined by solubility tests in various solvents.

Within the meaning of this invention, as particular solvents may be mentioned organic solvents which are wholly or partly water miscible, such as e.g. a suitable solvent for salt formation and/or crystallization is a low-molecular-weight aliphatic alcohol, e.g. ethanol, optionally in combination with water.

In a further aspect, the present invention relates to a process for preparing a salt of the invention, particularly in crystalline form, which comprises one or more of the steps of:

i.) forming a solution comprising 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine and an acid, such as e.g. any of those pharmaceutically acceptable acids described herein, particularly any of those described by way of example in the following examples, ii.) inducing crystallization of the salt e.g. from solution, and iii.) recovering the crystalline 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine salt.

In embodiments of this method, 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine and the acid are in 1:1 stoichiometry.

In further embodiments of this method, reacting and/or (re-)crystallization may be performed in an alcohol (particularly ethanol), optionally in the presence of water.

Salts prepared can be converted to another, e.g. by reaction with an appropriate acid or by means of a suitable ion exchanger. Likewise, salts obtained can be converted into the free compounds (e.g. via neutralization with a suitable base, with or without isolation of the free base, e.g. by extraction), which can in turn be converted into salts, by acidification. In this manner, physiologically unacceptable salts can be converted into physiologically acceptable salts.

In a further aspect, the present invention relates to salts of the invention (including their solvates and hydrates) in solid forms, including amorphous, semi-amorphous, polymorphous, semi-crystalline and crystalline forms, as well as mixtures thereof.

For more detailed example, the invention concerns the salts (including their solvates and hydrates whether mixed or not) of the invention in partially crystalline form (such as e.g. from about 5 to 20% crystalline) as well as in substantially crystalline form (such as e.g. greater than any of about 20, 30, 40, 50, 60, 70, 80, 90 or 95% crystalline).

The presence of crystal forms and degree (%) of crystallinity may be determined by the skilled person using X-ray powder diffraction (XRPD). Other techniques, such as solid state NMR, FT-IR, Raman spectroscopy, differential scanning calorimetry (DSC) and microcalorimetry, may also be used.

The crystalline forms and polymorphs of the salts of the present invention may be characterized by their melting points (obtained e.g. by DSC method) or by their respective x-ray powder diffraction spectra data or pattern comprising major peaks (e.g. with a relative intensity of greater than or equal about 10%, 20% or 25% or the like), as shown in the examples hereinafter. Such as for example, a crystalline form of the hydrochloride salt of this invention has the X-ray powder diffraction pattern essentially as defined in Table 10 and/or essentially as defined in FIG. 9.

Crystalline forms and polymorphs may be prepared by crystallization of a compound of this invention. Various crystallization techniques may be used to form and isolate crystalline compounds and polymorphs, such as e.g. any of those crystalline forming procedures described herein, such as, for example, crystallization or precipitation from a suitable solvent or solvent mixtures, stirring of a suspension (phase equilibration), slurrying, solvent evaporation, allowing or causing cooling to a suitable temperature to initiate crystallization, using suitable modes of cooling ranging from very fast to very slow cooling rates during crystallization, effecting a suitable pressure, using seeding crystals, re-crystallization, filtering, washing (e.g. in the crystallising solvent) and/or drying (e.g. under reduced pressure and/or at elevated temperature).

Crystalline forms may also be obtained by heating or melting a form obtained followed by gradual or fast cooling; in this manner one polymorph or one crystalline form may be converted to another.

In a further aspect, the present invention relates to salts of the invention (including their solvates, hydrates, polymorphs, crystalline and amorphous forms) in substantially pure form (e.g. substantially devoid of impurities and/or other forms), for example, in a degree of purity of about >80%, >85%, >90%, >95%, >98%, or >99% of the respective form.

In another aspect, the present invention relates to salts of the invention (including their solvates, hydrates, polymorphs, crystalline and amorphous forms) in substantially pure form, that means, for example, that the respective form includes less than 20%, less than 10%, less than 5%, less than 3% or less than 1% by weight of any impurities or other physical forms.

The present invention further relates to a salt as described herein for use in the treatment and/or prevention of metabolic diseases, particularly type 2 diabetes mellitus.

The present invention further relates to the use of a salt as described herein for the manufacture of a pharmaceutical composition for treating and/or preventing metabolic diseases, particularly type 2 diabetes mellitus.

The present invention further relates to a pharmaceutical composition for use in the treatment and/or prevention of metabolic diseases, particularly type 2 diabetes mellitus, said pharmaceutical composition comprising a salt as described herein and optionally one or more pharmaceutically acceptable carriers and/or diluents.

The present invention further relates to a fixed or non-fixed combination including a kit-of-parts for use in the treatment and/or prevention of metabolic diseases, particularly type 2 diabetes mellitus, said combination comprising a salt as described herein and optionally one or more other active substances, e.g. any of those mentioned herein.

The present invention further relates to the use of a salt as described herein in combination with one or more other active substances, such as e.g. any of those mentioned herein, for the manufacture of a pharmaceutical composition for treatment and/or prevention of metabolic diseases, particularly type 2 diabetes mellitus.

The present invention further relates to a pharmaceutical composition for use in the treatment and/or prevention of metabolic diseases, particularly type 2 diabetes mellitus, said pharmaceutical composition comprising a salt as described herein and optionally one or more other active substances, such as e.g. any of those mentioned herein.

The present invention further relates to a method of treating and/or preventing metabolic diseases, particularly type 2 diabetes mellitus, said method comprising administering to a subject in need thereof (particularly a human patient) an effective amount of a salt as described herein, optionally separately, sequentially, simultaneously, concurrently or chronologically staggered with an effective amount of one or more other active substances, such as e.g. any of those mentioned herein.

Further, the salts as described herein may be useful in one or more of the following methods

-   -   for preventing, slowing progression of, delaying, or treating a         metabolic disorder;     -   for improving glycemic control and/or for reducing of fasting         plasma glucose, of postprandial plasma glucose and/or of         glycosylated hemoglobin HbA1c;     -   for preventing, slowing, delaying or reversing progression from         impaired glucose tolerance, insulin resistance and/or from         metabolic syndrome to type 2 diabetes mellitus;     -   for preventing, slowing progression of, delaying or treating of         a condition or disorder selected from the group consisting of         complications of diabetes mellitus;     -   for reducing the weight or preventing an increase of the weight         or facilitating a reduction of the weight;     -   for preventing or treating the degeneration of pancreatic beta         cells and/or for improving and/or restoring the functionality of         pancreatic beta cells and/or stimulating and/or restoring the         functionality of pancreatic insulin secretion; and/or     -   for maintaining and/or improving the insulin sensitivity and/or         for treating or preventing hyperinsulinemia and/or insulin         resistance.

Examples of such metabolic diseases or disorders amenable by the therapy of this invention may include, without being restricted to, Type 1 diabetes, Type 2 diabetes, inadequate glucose tolerance, insulin resistance, hyperglycemia, hyperlipidemia, hypercholesterolemia, dyslipidemia, metabolic syndrome X, obesity, hypertension, chronic systemic inflammation, retinopathy, neuropathy, nephropathy, atherosclerosis, endothelial dysfunction and osteoporosis.

The compound 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine (compare WO 2004/018468, example 2 (142)), which is also known as BI 1356, has the formula:

The methods of synthesis for 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine are known to the skilled person. Advantageously, 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine can be prepared using synthetic methods as described in the literature. Thus, for example, it can be obtained as described in WO 2002/068420, WO 2004/018468 or WO 2006/048427, the disclosures of which are incorporated herein.

For pharmaceutical application in warm-blooded vertebrates, particularly humans, usually dosage levels from 0.001 to 100 mg/kg body weight, preferably at 0.1-15 mg/kg, in each case 1 to 4 times a day, of active ingredient may be used. For this purpose, the compounds, optionally combined with other active substances, may be incorporated together with one or more inert conventional carriers and/or diluents, e.g. with corn starch, lactose, glucose, microcrystalline cellulose, magnesium stearate, polyvinylpyrrolidone, citric acid, tartaric acid, water, water/ethanol, water/glycerol, water/sorbitol, water/polyethylene glycol, propylene glycol, cetylstearyl alcohol, carboxymethylcellulose or fatty substances such as hard fat or suitable mixtures thereof into conventional galenic preparations such as plain or coated tablets, capsules, powders, suspensions or suppositories.

Usual liquid or solid carrier materials are not only inorganic, but also organic carrier materials. Thus, for example, lactose, corn starch or derivatives thereof, talc, stearic acid or its salts may be used as carrier materials for tablets, coated tablets, dragees and hard gelatine capsules. Typical carrier materials for soft gelatine capsules are, for example, vegetable oils, waxes, fats and semi-solid and liquid polyols (depending on the nature of the active ingredient no carriers are, however, required in the case of soft gelatine capsules). Typical carrier materials for the production of solutions and syrups are, for example, water, polyols, sucrose, invert sugar and the like. Typical carrier materials for injection solutions are, for example, water, alcohols, polyols, glycerol and vegetable oils. Typical carrier materials for suppositories are, for example, natural or hardened oils, waxes, fats and semi-liquid or liquid polyols.

The pharmaceutical compositions according to this invention comprising the salts as defined herein are thus prepared by the skilled person using pharmaceutically acceptable formulation excipients as described in the art, such as e.g. those mentioned hereinabove and hereinbelow, of a type appropriate, e.g. to the desired formulation and to the desired mode of administration. The content of the active compound(s) is advantageously being from 0.1 to 95 wt % (weight percent of the final dosage form), particularly from 1 to 60 wt %. By means of the appropriate selection of the excipients, it is possible to obtain a pharmaceutical administration form adapted to the active ingredient(s) and/or to the desired onset and/or duration of action. Examples of such excipients include, without being restricted to, excipients commonly used for solid pharmaceutical forms (e.g. tablets), such as e.g. diluents, fillers, binders, carriers, lubricants, disintegrants, flow promoters, glidants and/or coating agents, excipients commonly used for liquid oral forms (e.g. syrups or elixirs), such as e.g. gel formers, wetting agents, antifoams, colorants, adsorbent agents, thickeners, flavorings and/or sweeteners, excipients commonly used for injection solutions or infusions, such as e.g. dispersants, emulsifiers, preservatives, solubilizers, buffer substances and/or isotonic adjusting substances, and other accessory excipients, such as e.g. stabilizers and/or solvents.

An embodiment of this invention refers to dosage forms for oral administration of the compounds of the invention. Tablets, coated tablets, dragees, pills, cachets, capsules, caplets, granules, solutions, emulsions and suspensions are e.g. suitable for oral administration. Solid oral dosage forms, such as e.g. capsules, tablets, pills, powders or granules, are hereby particularly concerned.

If desired, these formulations may also be adapted so as to represent, for example, an enteric form, an immediate release form, a delayed release form, a repeated dose release form, a prolonged release form or a sustained release form. Said forms can be obtained, for example, by coating tablets, by matrix techniques, by dividing tablets (e.g. their cores and/or coatings) into several compartments which may be separated by layers disintegrating under different conditions (e.g. pH conditions) or by coupling the compound of the invention to a biodegradable polymer.

In a certain embodiment, a compound of the invention is preferably in the form of a tablet. Such a tablet typically comprises the active ingredient(s) with one or more diluents, fillers and/or carriers, and, optionally, one or more binders, one or more lubricants, one or more disintegrants, and/or one or more glidants, as well as, if desired, a film overcoat.

Such a tablet may be obtained, for example, by mixing the active substance(s) with known excipients, for example which can be selected from those mentioned herein.

Coated tablets may be prepared by coating of cores (which may be produced analogously to the tablets) with substances normally used for tablet coatings (e.g. film-forming agents, plasticizers, glidants and/or pigments).

The tablet (including its core and coating) may also comprise several layers (e.g. mono-, bi- or trilayer), e.g. to achieve delayed release or to prevent incompatibilities.

Usually, in general as diluents/fillers one or more of mannitol, lactose, sucrose, maltodextrin, sorbitol, xylitol, powdered cellulose, microcrystalline cellulose, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylhydroxyethylcellulose, starch, sodium starch glycolate, pregelatinized starch, a calcium phosphate, a metal carbonate, a metal oxide or a metal aluminosilicate may come into consideration.

Usually, in general as binders one or more of polyvinylpyrrolidone, copovidone, hydroxypropylcellulose, hydroxypropylmethylcellulose, crosslinked poly(acrylic acid), gum arabic, gum acacia, gum tragacanath, lecithin, casein, polyvinyl alcohol, gelatin, kaolin, cellulose, methylcellulose, hydroxymethylcellulose, carboxymethylcellulose, carboxymethylcellulose calcium, carboxymethylcellulose sodium, hydroxypropylcellulose, hydroxypropylmethylcellulose phthalate, hydroxyethylcellulose, methylhydroxyethylcellulose, silicified microcrystalline cellulose, starch, maltodextrin, dextrins, microcrystalline cellulose or sorbitol may come into consideration.

Usually, in general as disintegrants one or more of croscarmellose sodium, carmellose calcium, crospovidone, alginic acid, sodium alginate, potassium alginate, calcium alginate, an ion exchange resin, an effervescent system based on food acids and an alkaline carbonate component, clay, talc, starch, pregelatinized starch, sodium starch glycolate, cellulose floe, carboxymethylcellulose, hydroxypropylcellulose, calcium silicate, a metal carbonate, sodium bicarbonate, calcium citrate or calcium phosphate may come into consideration.

Usually, in general as lubricants one or more of stearic acid, metallic stearate, sodium stearyl fumarate, fatty acid, fatty alcohol, fatty acid ester, glyceryl behenate, mineral oil, vegetable oil, paraffin, leucine, silica, silicic acid, talc, propylene glycol fatty acid ester, polyethylene glycol, polypropylene glycol, polyalkylene glycol or sodium chloride may come into consideration.

If desired, direct compression or granulation of the mixtures and/or components may be considered, which may be accomplished by conventional granulation techniques known to one of skill in the art. For example, dry granulation techniques include, but are not limited to, compression of the mixed powder under high pressure, either by roller compaction or “slugging” in a heavy-duty tablet press. Wet granulation techniques include, but are not limited to, high shear granulation, single-pot processing, top-spray granulation, bottom-spray granulation, fluidized spray granulation, extrusion/spheronization, and rotor granulation.

Examples of suitable diluents for compounds of this invention may include cellulose powder, calcium hydrogen phosphate, erythritol, low substituted hydroxypropyl cellulose, mannitol, pregelatinized starch or xylitol.

Examples of suitable lubricants for compounds of this invention may include talc, polyethyleneglycol, calcium behenate, calcium stearate, hydrogenated castor oil or magnesium stearate.

Examples of suitable binders for compounds of this invention may include copovidone (copolymerisates of vinylpyrrolidon with other vinylderivates), hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose (HPC), polyvinylpyrrolidon (povidone), pregelatinized starch, or low-substituted hydroxypropylcellulose (L-HPC).

Examples of suitable disintegrants for compounds of this invention may include corn starch or crospovidone.

Suitable methods of preparing pharmaceutical formulations of the compounds of this invention may be

-   -   direct tabletting of the active substance in powder mixtures         with suitable tabletting excipients;     -   granulation with suitable excipients and subsequent mixing with         suitable excipients and subsequent tabletting as well as film         coating; or     -   packing of powder mixtures or granules into capsules.

Suitable granulation methods may be

-   -   wet granulation in the intensive mixer followed by fluidised bed         drying;     -   one-pot granulation;     -   fluidised bed granulation; or     -   dry granulation (e.g. by roller compaction) with suitable         excipients and subsequent tabletting or packing into capsules.

Particular formulations and their preparation are described in the patent application WO 2007/128724, the contents of which are incorporated herein in their entirety for all purposes.

Within the present invention, the dosage typically required when administered intravenously is 0.1 mg to 10 mg, preferably 0.25 mg to 5 mg, and when administered orally is 0.5 mg to 100 mg, preferably 2.5 mg to 50 mg or 0.5 mg to 10 mg, more preferably 2.5 mg to 10 mg or 1 mg to 5 mg, in each case 1 to 4 times a day, of active ingredient. Thus, e.g. the dosage of 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine when administered orally is 0.5 mg to 10 mg per patient per day, preferably 2.5 mg to 10 mg or 1 mg to 5 mg per patient per day.

A dosage form prepared with a pharmaceutical composition comprising a salt as mentioned herein contain the active ingredient in a dosage range of 0.1-100 mg. Thus, e.g. particular dosage strengths of 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine are 0.5 mg, 1 mg, 2.5 mg, 5 mg and 10 mg.

A special embodiment of this invention refers to those orally administered DPP-4 inhibitors which are therapeutically efficacious at low dose levels, e.g. at dose levels <100 mg or <70 mg per patient per day, preferably <50 mg, more preferably <30 mg or <20 mg, even more preferably from 1 mg to 10 mg, particularly from 1 mg to 5 mg (more particularly 5 mg) of active ingredient, per patient per day, preferentially, administered orally once-daily, more preferentially, at any time of day, administered with or without food.

For details on dosage forms, formulations and administration of active substances, particularly of those indicated herein, reference is made to respective scientific literature and/or published patent documents, particularly to those cited herein.

As different metabolic functional disorders often occur simultaneously, it is quite often indicated to combine a number of different active principles with one another. Thus, depending on the functional disorders diagnosed, improved treatment outcomes may be obtained if a DPP-4 inhibitor is combined with active substances customary for the respective disorders, such as e.g. one or more active substances selected from among the other antidiabetic substances, especially active substances that lower the blood sugar level or the lipid level in the blood, raise the HDL level in the blood, lower blood pressure or are indicated in the treatment of atherosclerosis or obesity.

The compounds of this invention—besides their use in mono-therapy—may also be used in conjunction with other active substances, by means of which improved treatment results can be obtained. Such a combined treatment may be given as a free combination of the substances or in the form of a fixed combination, for example in a tablet or capsule. Pharmaceutical formulations of the combination partner needed for this may either be obtained commercially as pharmaceutical compositions or may be formulated by the skilled man using conventional methods. The active substances which may be obtained commercially as pharmaceutical compositions are described in numerous places in the prior art, for example in the list of drugs that appears annually, the “Rote Liste®” of the federal association of the pharmaceutical industry, or in the annually updated compilation of manufacturers' information on prescription drugs known as the “Physicians' Desk Reference”.

Examples of antidiabetic combination partners are metformin; sulphonylureas such as glibenclamide, tolbutamide, glimepiride, glipizide, gliquidon, glibornuride and gliclazide; nateglinide; repaglinide; thiazolidinediones such as rosiglitazone and pioglitazone; PPAR gamma modulators such as metaglidases; PPAR-gamma agonists such as GI 262570; PPAR-gamma antagonists; PPAR-gamma/alpha modulators such as tesaglitazar, muraglitazar and KRP297; PPAR-gamma/alpha/delta modulators; AMPK-activators such as AICAR; acetyl-CoA carboxylase (ACC1 and ACC2) inhibitors; diacylglycerol-acetyltransferase (DGAT) inhibitors; pancreatic beta cell GCRP agonists such as SMT3-receptor-agonists and GPR119; 11β-HSD-inhibitors; FGF19 agonists or analogues; alpha-glucosidase blockers such as acarbose, voglibose and miglitol; alpha2-antagonists; insulin and insulin analogues such as human insulin, insulin lispro, insulin glusilin, r-DNA-insulinaspart, NPH insulin, insulin detemir, insulin zinc suspension and insulin glargin; Gastric inhibitory Peptide (GIP); pramlintide; amylin or GLP-1 and GLP-1 analogues such as Exendin-4; SGLT2-inhibitors such as KGT-1251; inhibitors of protein tyrosine-phosphatase; inhibitors of glucose-6-phosphatase; fructose-1,6-bisphosphatase modulators; glycogen phosphorylase modulators; glucagon receptor antagonists; phosphoenolpyruvatecarboxykinase (PEPCK) inhibitors; pyruvate dehydrogenasekinase (PDK) inhibitors; inhibitors of tyrosine-kinases (50 mg to 600 mg) such as PDGF-receptor-kinase (cf. EP-A-564409, WO 98/35958, U.S. Pat. No. 5,093,330, WO 2004/005281, and WO 2006/041976); glucokinase/regulatory protein modulators incl. glucokinase activators; glycogen synthase kinase inhibitors; inhibitors of the SH2-domain-containing inositol 5-phosphatase type 2 (SHIP2); IKK inhibitors such as high-dose salicylate; JNK1 inhibitors; protein kinase C-theta inhibitors; beta 3 agonists such as ritobegron, YM 178, solabegron, talibegron, N-5984, GRC-1087, rafabegron, FMP825; aldosereductase inhibitors such as AS 3201, zenarestat, fidarestat, epalrestat, ranirestat, NZ-314, CP-744809, and CT-112; SGLT-1 or SGLT-2 inhibitors; KV 1.3 channel inhibitors; GPR40 modulators; SCD-1 inhibitors; CCR-2 antagonists; and other DPP IV inhibitors.

Metformin is usually given in doses varying from about 500 mg to 2000 mg up to 2500 mg per day using various dosing regimens from about 100 mg to 500 mg or 200 mg to 850 mg (1-3 times a day), or about 300 mg to 1000 mg once or twice a day, or delayed-release metformin in doses of about 100 mg to 1000 mg or preferably 500 mg to 1000 mg once or twice a day or about 500 mg to 2000 mg once a day. Particular dosage strengths may be 250, 500, 625, 750, 850 and 1000 mg of metformin hydrochloride.

A dosage of pioglitazone is usually of about 1-10 mg, 15 mg, 30 mg, or 45 mg once a day, e.g. used as pioglitazone hydrochloride.

Glibenclamide (glyburide) is usually given in doses from 2.5 to 20 mg once (or twice) a day (typical dosage strengths are 1.25, 2.5 and 5 mg), or micronized glibenclamide in doses from 0.75 to 12 mg once a day (typical dosage strengths are 1.5, 3, 4.5 and 6 mg).

Glipizide is usually given in doses from 2.5 to 40 mg once (or twice) a day (typical dosage strengths are 5 and 10 mg), or extended-release glibenclamide in doses from 5 to 20 mg once a day (typical dosage strengths are 2.5, 5 and 10 mg).

Glimepiride is usually given in doses from 1 to 8 mg once a day (typical dosage strengths are 1, 2 and 4 mg).

A dual combination of glibenclamide/metformin is usually given in doses from 1.25/250 once daily to 10/1000 mg twice daily.

A dual combination of glipizide/metformin is usually given in doses from 2.5/250 to 10/1000 mg twice daily.

A dual combination of glimepiride/metformin is usually given in doses from 1/250 to 4/1000 mg twice daily.

A dual combination of rosiglitazone/glimepiride is usually given in doses from 4/1 once or twice daily to 4/2 mg twice daily.

A dual combination of pioglitazone/glimepiride is usually given in doses from 30/2 to 30/4 mg once daily.

A dual combination of rosiglitazone/metformin is usually given in doses from 1/500 to 4/1000 mg twice daily.

A dual combination of pioglitazone/metformin is usually given in doses from 15/500 once or twice daily to 15/850 mg thrice daily.

The non-sulphonylurea insulin secretagogue nateglinide is usually given in doses from 60 to 120 mg with meals; repaglinide is usually given in doses from 0.5 to 4 mg with meals.

Acarbose is usually given in doses from 25 to 100 mg with meals. Miglitol is usually given in doses from 25 to 100 mg with meals.

Examples of combination partners that lower the lipid level in the blood are HMG-CoA-reductase inhibitors such as simvastatin, atorvastatin, lovastatin, fluvastatin, pravastatin and rosuvastatin; fibrates such as bezafibrate, fenofibrate, clofibrate, gemfibrozil, etofibrate and etofyllinclofibrate; nicotinic acid and the derivatives thereof such as acipimox; PPAR-alpha agonists; PPAR-delta agonists; inhibitors of acyl-coenzyme A:cholesterolacyltransferase (ACAT; EC 2.3.1.26) such as avasimibe; cholesterol resorption inhibitors such as ezetimib; substances that bind to bile acid, such as cholestyramine, colestipol and colesevelam; inhibitors of bile acid transport; HDL modulating active substances such as D4F, reverse D4F, LXR modulating active substances and FXR modulating active substances; CETP inhibitors such as torcetrapib, JTT-705 or compound 12 from WO 2007/005572; LDL receptor modulators; and ApoB100 antisense RNA.

A dosage of atorvastatin is usually from 1 mg to 40 mg or 10 mg to 80 mg once a day

Examples of combination partners that lower blood pressure are beta-blockers such as atenolol, bisoprolol, celiprolol, metoprolol and carvedilol; diuretics such as hydrochlorothiazide, chlortalidon, xipamide, furosemide, piretanide, torasemide, spironolactone, eplerenone, amiloride and triamterene; calcium channel blockers such as amlodipine, nifedipine, nitrendipine, nisoldipine, nicardipine, felodipine, lacidipine, lercanipidine, manidipine, isradipine, nilvadipine, verapamil, gallopamil and diltiazem; ACE inhibitors such as ramipril, lisinopril, cilazapril, quinapril, captopril, enalapril, benazepril, perindopril, fosinopril and trandolapril; as well as angiotensin II receptor blockers (ARBs) such as telmisartan, candesartan, valsartan, losartan, irbesartan, olmesartan and eprosartan.

A dosage of telmisartan is usually from 20 mg to 320 mg or 40 mg to 160 mg per day.

Examples of combination partners which increase the HDL level in the blood are Cholesteryl Ester Transfer Protein (CETP) inhibitors; inhibitors of endothelial lipase; regulators of ABC1; LXRalpha antagonists; LXRbeta agonists; PPAR-delta agonists; LXRalpha/beta regulators, and substances that increase the expression and/or plasma concentration of apolipoprotein A-I.

Examples of combination partners for the treatment of obesity are sibutramine; tetrahydrolipstatin (orlistat); alizyme; dexfenfluramine; axokine; cannabinoid receptor 1 antagonists such as the CB1 antagonist rimonobant; MCH-1 receptor antagonists; MC4 receptor agonists; NPY5 as well as NPY2 antagonists; beta3-AR agonists such as SB-418790 and AD-9677; 5HT2c receptor agonists such as APD 356; myostatin inhibitors; Acrp30 and adiponectin; steroyl CoA desaturase (SCD1) inhibitors; fatty acid synthase (FAS) inhibitors; CCK receptor agonists; Ghrelin receptor modulators; Pyy 3-36; orexin receptor antagonists; and tesofensine.

Examples of combination partners for the treatment of atherosclerosis are phospholipase A2 inhibitors; inhibitors of tyrosine-kinases (50 mg to 600 mg) such as PDGF-receptor-kinase (cf. EP-A-564409, WO 98/35958, U.S. Pat. No. 5,093,330, WO 2004/005281, and WO 2006/041976); oxLDL antibodies and oxLDL vaccines; apoA-1 Milano; ASA; and VCAM-1 inhibitors.

It is to be understood that the other active substances mentioned herein as combination partners of the salts of this invention also comprise their pharmaceutically acceptable salts as well as hydrates, solvates and polymorphic forms thereof.

The present invention is not to be limited in scope by the specific embodiments described herein. Various modifications of the invention in addition to those described herein may become apparent to those skilled in the art from the present disclosure. Such modifications are intended to fall within the scope of the appended claims.

For avoidance of any doubt, the disclosure of each of the documents and patent applications cited herein is specifically incorporated herein by reference in its entirety.

Further embodiments, features and advantages of the present invention may become apparent from the following examples. The following examples serve to illustrate, by way of example, the principles of the invention without restricting it.

EXAMPLES Synthesis/Preparation

0.5 g of the free base of BI 1356 are suspended at room temperature in 4 ml of EtOH. The suspension is heated under reflux until a clear solution is obtained which typically is obtained after a few minutes. 1 mol equivalent of the respective acid (see Table 1), either dissolved in EtOH or water is added to the hot solution of BI 1356. Afterwards heating is removed and the solution is slowly cooled down and stored over night at room temperature. In case precipitation is observed, the obtained crystals are removed by filtering and afterwards dried over night at ambient conditions. In case no precipitation was observed the solution is evaporated partially (by approx. 50%) and than stored for another night in the refrigerator (4° C.). Precipitated crystals are also removed by filtering and afterwards dried over night at ambient conditions. The obtained crystals are analysed by polarized light microscopy, X-ray powder diffraction and thermal analysis.

Used Equipment for X-Ray Powder Diffraction Measurements:

STOE Stadi P X-ray powder diffractometer with a position sensitive detector working in transmission mode with a curved Germanium (111) primary monochromator; used wavelength: CuK_(αI) mit λ=1.540598 Å; power settings of X-ray tube: 40 kV, 40 mA; 2

-range: 3-40°

For indexing of the X-ray powder patterns where single crystal structure data is available the program TREOR was used which is part of the STOE Stadi P software package. Tables 2-13 show the characteristic X-ray peaks including normalised intensities up to 30° in 2

. The respective XRPD—diagrams are shown in FIGS. 1-12 in the appendix.

Used Equipment for Thermoanalysis:

A DSC 822 from Fa. Mettler Toldeo was used. The following standard parameters were applied: heating rate: 10 K/min; crucible type: pin-holed aluminium crucible; atmosphere: N₂, 80 ml/min flow rate; typical weight-in quantities: 3-10 mg.

A TGA/SDTA 851 from Mettler Toledo coupled with a Nicolet FT-IR 4700 spectrometer was used (for analysis of volatile material). The following standard parameters were applied: heating rate: 10 K/min; crucible type: open aluminium oxide crucible; atmosphere: N₂, 20 ml/min flow rate; typical weight-in quantities: 15-25 mg.

The melting point (=T_(fus)) measured by DSC is given in Table 1.

TABLE 1 Salt formation of BI 1356 stoichi- salt form ometry thermal analysis (used acid) base:c.i. (m.p.) XRPD-data besylate 1:1 T_(fus): ca. 175° C. see Tab. 2 (benzenesulfonic acid) & FIG. 1 bromide 1:1 T_(fus): ca. 175° C. see Tab. 3 (hydrobromic acid) & FIG. 2 benzoate 1:1 T_(fus): ca. 155° C. see Tab. 4 (benzoic acid) & FIG. 3 esylate 1:1 T_(fus): ca. 190° C. see Tab. 5 (ethanesulfonic acid) & FIG. 4 fumarate 1:1 T_(fus): ca. 225° C. see Tab. 6 (fumaric acid) & FIG. 5 mesylate 1:1 T_(fus): ca. 160° C. see Tab. 7 (methanesulfonic acid) & FIG. 6 salicylate 1:1 T_(fus): ca. 165° C. see Tab. 8 (salicylic acid) & FIG. 7 tosylate 1:1 T_(fus): ca. 160° C. see Tab. 9 (p-toluenesulfonic acid) & FIG. 8 chloride 1:1 T_(fus): ca. 175° C. see Tab. 10 (hydrochloric acid) & FIG. 9 glyoclate 1:1 T_(fus): ca. 165° C. see Tab. 11 (glycolic acid) & FIG. 10 malonate 1:1 T_(fus): ca. 100° C. see Tab. 12 (malonic acid) & FIG. 11 gentisate 1:1 T_(fus): ca. 170° C. see Tab. 13 (2,5-dihydroxybenzoic & FIG. 12 acid)

TABLE 2 X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of the besylate salt of BI 1356 2 Θ d_(hkl) [°] [Å] I/I_(o) 3.95 22.37 41 7.35 12.02 12 7.86 11.24 37 9.73 9.09 67 10.95 8.07 15 11.95 7.40 100 13.18 6.71 14 14.71 6.02 16 15.12 5.85 46 15.49 5.71 50 17.38 5.10 16 18.25 4.86 26 19.01 4.66 81 19.95 4.45 19 21.49 4.13 27 22.59 3.93 52 23.15 3.84 25 24.16 3.68 16 25.71 3.46 22 26.60 3.35 14 27.32 3.26 15 28.44 3.14 6 29.60 3.02 6

TABLE 3 X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of the bromide salt of BI 1356 2 Θ d_(hkl) [°] [Å] I/I_(o) 4.14 21.31 29 8.31 10.63 36 9.53 9.27 100 10.43 8.48 31 11.62 7.61 49 11.83 7.47 32 12.58 7.03 58 13.31 6.64 9 14.45 6.13 24 15.03 5.89 42 15.67 5.65 23 16.66 5.32 41 17.23 5.14 34 19.17 4.63 41 19.57 4.53 23 19.80 4.48 88 20.84 4.26 27 21.43 4.14 20 21.82 4.07 83 22.19 4.00 56 22.75 3.91 48 23.57 3.77 33 23.84 3.73 27 24.10 3.69 19 24.67 3.61 17 25.32 3.51 84 27.51 3.24 23 27.78 3.21 29 29.17 3.06 26

TABLE 4 X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of the benzoate salt of BI 1356 2 Θ d_(hkl) [°] [Å] I/I_(o) 3.91 22.56 88 7.82 11.30 6 9.75 9.06 100 10.84 8.16 11 11.38 7.77 19 11.76 7.52 59 12.26 7.22 22 13.04 6.78 6 14.76 6.00 11 15.29 5.79 12 15.94 5.56 25 16.35 5.42 25 16.95 5.23 28 18.17 4.88 25 18.86 4.70 71 19.28 4.60 7 19.60 4.53 8 20.32 4.37 12 21.49 4.13 19 21.76 4.08 11 22.07 4.02 6 22.40 3.97 23 23.23 3.83 8 23.76 3.74 47 24.34 3.65 10 24.64 3.61 21 25.22 3.53 3 25.90 3.44 15 26.07 3.42 13 26.85 3.32 6 27.43 3.25 14 28.02 3.18 5 28.52 3.13 10 28.87 3.09 4 29.84 2.99 8

TABLE 5 X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of the esylate salt of BI 1356 2 Θ d_(hkl) [°] [Å] I/I_(o) 4.06 21.75 46 8.12 10.87 30 9.70 9.11 100 10.74 8.23 24 11.51 7.68 40 11.83 7.48 69 12.35 7.16 10 12.59 7.03 8 14.52 6.09 17 15.17 5.83 46 16.07 5.51 15 16.32 5.43 44 16.79 5.28 26 18.15 4.88 18 18.47 4.80 23 18.78 4.72 21 19.56 4.53 60 20.37 4.36 23 21.45 4.14 32 21.64 4.10 28 22.41 3.96 53 23.35 3.81 10 24.19 3.68 9 24.76 3.59 24 24.98 3.56 25 25.30 3.52 8 25.99 3.43 5 26.83 3.32 17 27.08 3.29 12 28.10 3.17 10 29.32 3.04 5

TABLE 6 X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of the fumarate salt of BI 1356 2 Θ d_(hkl) [°] [Å] I/I_(o) 4.23 20.86 36 6.06 14.58 15 8.24 10.72 100 9.92 8.91 34 10.82 8.17 21 11.69 7.56 28 12.26 7.22 70 12.43 7.12 39 12.89 6.86 43 13.70 6.46 36 13.87 6.38 15 14.50 6.10 13 15.19 5.83 17 15.98 5.54 39 16.67 5.31 25 18.75 4.73 37 20.16 4.40 13 20.30 4.37 20 20.58 4.31 32 20.93 4.24 24 21.25 4.18 20 21.93 4.05 40 22.57 3.94 24 23.47 3.79 21 23.71 3.75 30 24.09 3.69 28 24.42 3.64 46 25.04 3.55 22 25.67 3.47 19 25.90 3.44 7 26.62 3.35 14 26.94 3.31 16 27.22 3.27 25 27.50 3.24 25 29.19 3.06 7

TABLE 7 X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of the mesylate salt of BI 1356 2 Θ d_(hkl) [°] [Å] I/I_(o) 4.15 21.29 71 8.29 10.66 83 9.59 9.22 93 10.59 8.35 12 11.56 7.65 66 11.80 7.49 70 12.42 7.12 39 12.57 7.03 56 14.45 6.12 17 14.91 5.94 25 15.16 5.84 31 15.40 5.75 72 16.05 5.52 26 16.47 5.38 80 17.03 5.20 35 17.32 5.12 19 18.02 4.92 15 18.38 4.82 15 18.83 4.71 27 19.58 4.53 98 19.87 4.46 27 20.14 4.41 14 20.61 4.31 46 21.61 4.11 75 22.15 4.01 20 22.51 3.95 100 23.38 3.80 22 23.72 3.75 15 23.96 3.71 20 24.16 3.68 14 25.02 3.56 93 25.29 3.52 25 26.60 3.35 27 27.01 3.30 17 27.60 3.23 16 28.15 3.17 20 29.20 3.06 11

TABLE 8 X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of salicylate salt of BI 1356 2 Θ d_(hkl) [°] [Å] I/I_(o) 3.91 22.61 100 7.79 11.33 6 9.85 8.97 69 11.15 7.93 12 11.74 7.53 59 12.12 7.30 12 12.86 6.88 7 14.77 5.99 8 15.08 5.87 11 15.32 5.78 14 15.69 5.64 23 15.98 5.54 12 16.42 5.39 16 17.05 5.20 10 18.27 4.85 20 18.74 4.73 23 18.92 4.69 34 19.95 4.45 18 20.32 4.37 7 21.41 4.15 12 21.96 4.04 9 22.46 3.96 8 23.10 3.85 8 23.52 3.78 62 24.34 3.65 11 25.16 3.54 6 25.87 3.44 9 26.69 3.34 7 27.50 3.24 10 28.85 3.09 4 29.69 3.01 3 30.28 2.95 10

TABLE 9 X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of tosylate salt of BI 1356 2 Θ d_(hkl) [°] [Å] I/I_(o) 3.79 23.32 25 7.58 11.66 10 7.74 11.42 14 10.05 8.79 18 11.20 7.89 27 11.96 7.39 100 12.42 7.12 33 12.79 6.92 16 13.34 6.63 7 14.34 6.17 39 15.47 5.72 16 15.99 5.54 23 16.46 5.38 13 17.55 5.05 8 18.47 4.80 12 18.85 4.70 20 20.05 4.42 50 21.22 4.18 43 21.61 4.11 19 22.14 4.01 59 22.79 3.90 10 23.42 3.80 10 24.03 3.70 29 24.55 3.62 24 26.62 3.35 16 27.62 3.23 15

TABLE 10 Indexed X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of the tetrahydrate of the hydrochloride of BI 1356 2 Θ d_(hkl) Indexing 2 Θ_(obs) − 2 Θ_(calc) [°] [Å] I/I_(o) h k l [°] 4.52 19.55 43 0 0 1 0.002 9.86 8.97 100 2 0 0 −0.002 10.56 8.37 7 −2 0 1 0.001 11.60 7.62 70 0 1 1 0.011 11.77 7.52 64 1 1 0 0.005 12.49 7.08 92 −1 1 1 0.006 12.72 6.95 13 1 1 1 −0.005 13.83 6.40 58 2 0 2 −0.007 15.04 5.89 56 −2 1 1 0.005 15.43 5.74 41 2 1 1 −0.006 16.78 5.28 6 −2 1 2 −0.009 17.50 5.06 42 2 1 2 −0.006 18.28 4.85 6 1 1 3 0.028 19.08 4.65 47 3 1 1 −0.008 19.47 4.56 17 −3 0 3 0.036 20.00 4.44 27 −3 1 2 0.029 20.61 4.31 8 4 0 1 −0.002 20.90 4.25 16 3 1 2 0.017 21.44 4.14 29 0 2 0 −0.003 22.01 4.04 49 1 2 0 −0.003 22.37 3.97 96 4 0 2 0.013 22.78 3.90 16 −2 1 4 −0.002 23.44 3.79 35 3 1 3 −0.010 23.95 3.71 12 −2 2 1 −0.010 24.22 3.67 10 2 2 1 <0.001 24.82 3.58 61 5 0 0 0.017 25.12 3.54 78 −2 2 2 0.004 25.64 3.47 27 2 2 2 0.033 26.13 3.41 7 1 2 3 0.004 26.38 3.38 18 −3 0 5 0.040 27.38 3.25 20 −3 2 2 0.001 27.75 3.21 25 5 1 1 <0.001 28.47 3.13 22 −1 2 4 0.036 29.14 3.06 16 5 1 2 −0.006 29.49 3.03 20 −4 2 1 0.008 Indexing is possible with a monoclinic cell, space group P21, with the following lattice parameters: a = 17.974(4) Å, b = 8.282(3) Å, c = 19.607(6), β = 93.9(2)°, V = 2912(2) Å3. All 35 peaks can be indexed with a figure of merit of 42.1

TABLE 11 X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of glycolate salt of BI 1356 2 Θ d_(hkl) [°] [Å] I/I_(o) 3.16 27.94 18 5.54 15.95 4 6.35 13.90 100 8.41 10.51 31 9.55 9.25 15 11.05 8.00 5 11.48 7.70 26 13.88 6.37 13 15.94 5.56 14 17.81 4.98 2 18.11 4.90 2 18.96 4.68 4 19.45 4.56 4 19.95 4.45 10 21.01 4.22 29 21.97 4.04 3 22.67 3.92 26 23.12 3.84 14 24.01 3.70 2 24.63 3.61 2 25.27 3.52 7 26.49 3.36 8 26.88 3.31 13 27.65 3.22 7 28.75 3.10 1 29.44 3.03 2 30.21 2.96 1

TABLE 12 X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of malonate salt of BI 1356 2 Θ d_(hkl) [°] [Å] I/I_(o) 4.14 21.34 62 7.96 11.10 11 8.30 10.65 40 9.67 9.14 51 10.14 8.72 5 10.39 8.50 10 11.48 7.70 39 11.76 7.52 35 11.97 7.39 15 12.52 7.06 100 13.54 6.53 5 14.45 6.12 11 14.97 5.91 19 15.10 5.86 16 15.52 5.71 35 16.07 5.51 4 16.50 5.37 54 17.01 5.21 14 17.28 5.13 19 18.07 4.91 17 18.44 4.81 31 18.67 4.75 13 18.95 4.68 11 19.32 4.59 20 19.70 4.50 60 19.98 4.44 13 20.55 4.32 23 20.86 4.25 14 21.50 4.13 33 21.73 4.09 38 22.37 3.97 33 22.75 3.91 71 23.51 3.78 31 24.00 3.70 21 25.19 3.53 57 25.89 3.44 10 26.45 3.37 8 26.87 3.32 17 27.53 3.24 16 28.14 3.17 13 28.75 3.10 4 29.22 3.05 11 29.46 3.03 11

TABLE 13 X-ray diffraction peaks (up to 30° 2 Θ) including normalised intensities of gentisate salt of BI 1356 2 Θ d_(hkl) [°] [Å] I/I_(o) 4.06 21.73 100 9.69 9.12 90 10.83 8.16 11 11.30 7.83 75 11.72 7.55 85 13.15 6.73 12 14.34 6.17 20 14.70 6.02 31 15.14 5.85 21 15.70 5.64 11 16.15 5.48 35 16.50 5.37 8 16.89 5.24 15 18.02 4.92 7 18.71 4.74 6 19.08 4.65 25 19.41 4.57 64 21.15 4.20 23 21.37 4.16 18 21.80 4.07 11 22.33 3.98 7 22.72 3.91 10 23.21 3.83 26 23.85 3.73 81 24.20 3.67 30 24.51 3.63 16 24.92 3.57 18 25.79 3.45 18 25.99 3.43 13 26.27 3.39 9 26.81 3.32 8 27.32 3.26 9 27.84 3.20 5 28.62 3.12 5 29.27 3.05 8 29.61 3.01 8 29.96 2.98 9 

1. A salt of 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine and a pharmaceutically acceptable acid in a 1:1 stoichiometry.
 2. An acid addition salt of 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine with an acid selected from hydrochloric acid, hydrobromic acid, phosphoric acid, nitric acid, sulfuric acid, acetic acid, 2,2-dichloroacetic acid, adipic acid, D-ascorbic acid, L-ascorbic acid, D-aspartic acid, L-aspartic acid, benzenesulfonic acid, benzoic acid, 4-acetamido-benzoic acid, (+)-camphoric acid, (−)-camphoric acid, (+)-camphor-10-sulfonic, (−)-camphor-10-sulfonic, capric acid (decanoic acid), caproic acid (hexanoic acid), caprylic acid (octanoic acid), carbonic acid, cinnamic acid, citric acid, cyclamic acid, dodecylsulfuric acid, ethane-1,2-disulfonic acid, ethanesulfonic acid, 2-hydroxy-ethanesulfonic acid, formic acid, fumaric acid, galactaric acid, gentisic acid, D-glucoheptonic acid, L-glucoheptonic acid, D-gluconic acid, L-gluconic acid; D glucuronic acid, L-glucuronic acid, glutamic acid, glutaric acid, 2-oxo-glutaric acid, glycerophosphoric acid, glycolic acid, hippuric acid, isobutyric acid, D-lactic acid, L-lactic acid, lactobionic acid, lauric acid, maleic acid, D-malic acid, L-malic acid, malonic acid, D-mandelic acid, L-mandelic acid, methanesulfonic acid, naphthalene-1,5-disulfonic acid, naphthalene-2-sulfonic acid, 1-hydroxy-2-naphthoic acid, nicotinic acid, oleic acid, orotic acid, oxalic acid, palmitic acid, pamoic acid (embonic acid), propionic acid, D-pyroglutamic acid, L-pyroglutamic acid, salicyclic acid, 4-aminosalicyclic acid, sebacic acid, stearic acid, succinic acid, D-tartaric acid, L-tartaric acid, thiocyanic acid, p-toluenesulfonic acid and undecylenic acid, or an organic solvate, hydrate, or mixed hydrate/organic solvate thereof.
 3. The salt according to claim 2, which is selected from the group consisting of a besylate salt, a hydrobromide salt, a benzoate salt, an esylate salt, a fumarate salt, a mesylate salt, a salicylate salt, a tosylate salt, a hydrochloride salt, a glycolate salt, a malonate salt and a gentisate salt, or an organic solvate, hydrate, or mixed hydrate/organic solvate thereof.
 4. The salt according to claim 2, in the form of a solvate.
 5. The salt according to claim 2, in the form of an organic solvate.
 6. The salt according to claim 2, in the form of a hydrate.
 7. The salt according to claim 2, in the form of a mixed hydrate/organic solvate.
 8. The salt according to claim 2, in crystalline, partially crystalline, amorphous or polymorphous form.
 9. A pharmaceutical composition comprising a salt according to claim 1, optionally together with one or more pharmaceutically acceptable carriers and/or diluents.
 10. The pharmaceutical composition according to claim 9, further comprising one or more other active substances.
 11. A method of making a pharmaceutical composition comprising: mixing a salt according to claim 1, and one or more pharmaceutically acceptable excipients, and, optionally, one or more other active substances.
 12. A method for treating and/or preventing a disease, disorder or condition mediated by the enzyme DPP 4, comprising administering to a subject in need thereof, a therapeutically effective amount of a salt according to claim 1, optionally in combination with one or more other therapeutically active agents.
 13. (canceled)
 14. An organic solution of a salt according to claim 1, said solution optionally further comprising water.
 15. The organic solution of claim 14, wherein the organic solvent is ethanol, optionally with water.
 16. The method of claim 12, wherein the disease, disorder or condition mediated by the enzyme DPP-4 is type 2 diabetes mellitus.
 17. A process for preparing an acid addition salt according to claim 1 comprising i.) forming a solution comprising 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine and the acid.
 18. The process according to claim 17, further comprising ii.) inducing crystallization of the salt formed in Step (i) of claim 17, and iii.) recovering the crystalline 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine salt. 